KKR, Blackstone and TPG initially fought allegations of collusion but now they are settling without admitting or denying guilt.

NEW YORK (TheStreet) -- KKR (KKR), Blackstone Group (BX), and TPG Capital have settled a class action lawsuit alleging that the company, along with over a dozen banks and private-equity firms, colluded on pre-crisis buyout deals. The buyout firms initially fought those allegations but they now settling for a total of $325 million without admitting or denying guilt.

In 2007, over a dozen banks and PE firms were sued by plaintiffs in a Massachusetts court of working to artificially keep buyout prices low by refusing to bid against each other.

The suit mostly involved so-called club buyout deals that were once the rage in the private-equity industry. In those deals, groups of PE firms and banks built buyout consortiums to bid on publicly traded companies with market capitalizations as large as $30 billion. While club deals have fallen out of favor since the financial crisis, the collusion lawsuit has loomed over the private-equity industry for years.

Goldman Sachs (GS), Bain Capital and Silver Lake Partners earlier this year settled claims against them on the class-action lawsuit, with Goldman and Bain paying a combined $121 million to resolve claims without admitting or denying guilt.

Now, KKR, Blackstone and TPG are joining those PE peers after agreeing to a settlement that is scheduled to go in front of a judge in early September.

KKR disclosed Thursday's settlement in the firm's quarterly 10-Q filing with the Securities and Exchange Commission, however, the firm didn't specify what it will be paying. The company said it isn't expected to have a material effect on KKR's financial results.